1. Field of the Invention
The invention relates to a sliver divider on a textile machine, in particular on a drafting arrangement of a spinning machine, for dividing a sliver band into at least two strands that are delivered to a work station for further processing.
2. Description of the Related Art
Prior to the spinning process, the fibers to be processed must be prepared. In cotton, for instance, this is done by opening the bales, removing fibers from the bales, cleaning them and then depositing them as a web on a carder. To increase the cleanness of the fibers, improve their quality, or mix them with other fibers, strands can be produced from this card sliver that are in turn joined with the strands of other card slivers, mixed, and then drawn, in order finally to be deposited as sliver in a can, or wound to make a roving bobbin. So-called sliver dividers can already be used during the step of unraveling the web.
Prior to the spinning process, the sliver, deposited in cans or wound onto roving bobbins, undergoes a further preparation step. This includes paralleling of the fibers and attenuating the so-called feed roving in a drafting arrangement. There may also be sliver dividers within this drafting arrangement, which subdivide the partly drawn sliver still further, for the sake of further doubling or to produce twisted yarns. Drafting arrangements with sliver dividers are therefore especially found in air spinning machines, friction spinning machines and ring spinning machines.
The sliver dividers are disposed stationary in the travel route of the sliver. Usually, the sliver divider is located inside a sliver guide. In drafting arrangements on a spinning machine, the sliver divider is usually located between two devices for drafting the sliver, for instance between two apron-type drafting mechanisms. In other words, as seen in a direction of travel of the sliver, a drafting mechanism is followed by a sliver divider which is again followed by a drafting mechanism. German Published, Non-Prosecuted Patent Application 38 42 120, for instance, discloses a drafting mechanism provided with a so-called sliver parting and guiding apparatus, which comprises a shaft with a rotary element mounted on it and two laterally rotating sliver guides. This sliver parting and guiding apparatus is rotatable at right angles to the plane in which the sliver is transported, but otherwise is disposed in a stationary manner. The sliver is divided as if by a circular saw.
However, if a sliver divider is disposed rigidly, is it possible that the sliver may not be divided uniformly.
Depending on the sliver rotation and compression, the sliver may "creep" within the drafting arrangement. In this case, creep means that, because of nonuniform fiber distribution within the sliver, the sliver may swerve laterally away from its original path. With uneven drafting, the sliver creeps out of its path and no longer arrives at the sliver divider in the intended way. Accordingly, the sliver is no longer divided in the desired manner. In the least favorable case, the sliver divider may lose its function entirely, because the sliver may squeeze into one of the intended division paths, completely missing the sliver divider, therefore no longer being divided.
It is accordingly an object of the invention to provide a sliver divider, which overcomes the above-mentioned disadvantages of the heretofore-known devices of this general type, and which, even in the event of sliver creepage, always adheres to an initially desired division of the sliver.